Jurassic Marine Reptiles Research Articles

Palaeoepidemiology in extinct vertebrate populations: factors influencing skeletal health in Jurassic marine reptiles.

Palaeoepidemiological studies related to palaeoecology are rare, but have the potential to provide information regarding ecosystem-level characteristics by measuring individual health. In order to assess factors underlying the prevalence of pathologies in large marine vertebrates, we surveyed ichthyosaurs (Mesozoic marine reptiles) from the Posidonienschiefer Formation (Early Jurassic: Toarcian) of southwestern Germany. This Formation provides a relatively large sample from a geologically and geographically restricted interval, making it ideal for generating baseline data for a palaeoepidemiological survey. We examined the influence of taxon, anatomical region, body size, ontogeny and environmental change, as represented by the early Toarcian Oceanic Anoxic Event, on the prevalence of pathologies, based on a priori ideas of factors influencing population skeletal health. Our results show that the incidence of pathologies is dependent on taxon, with the small-bodied genus Stenopterygius exhibiting fewer skeletal pathologies than other genera. Within Stenopterygius, we detected more pathologies in large adults than in smaller size classes. Stratigraphic horizon, a proxy for palaeoenvironmental change, did not influence the incidence of pathologies in Stenopterygius. The quantification of the occurrence of pathologies within taxa and across guilds is critical to constructing more detailed hypotheses regarding changes in the prevalence of skeletal injury and disease through Earth history.

Новое местонахождение юрских морских рептилий на европейском севере России

Новое местонахождение юрских морских рептилий на европейском севере России

Pathological survey on Temnodontosaurus from the Early Jurassic of southern Germany.

Paleopathologies document skeletal damage in extinct organisms and can be used to infer the causes of injury, as well as aspects of related biology, ecology and behavior. To date, few studies have been undertaken on Jurassic marine reptiles, while ichthyosaur pathologies in particular have never been systematically evaluated. Here we survey 41 specimens of the apex predator ichthyosaur Temnodontosaurus from the Early Jurassic of southern Germany in order to document the range and absolute frequency of pathologies observed in this taxon as a function of the number of specimens examined. According to our analysis, most observed pathologies in Temnodontosaurus are force-induced traumas with signs of healing, possibly inflicted during aggressive interactions with conspecifics. When the material is preserved, broken ribs are correlated in most of the cases with traumas elsewhere in the skeleton such as cranial injuries. The range of cranial pathologies in Temnodontosaurus is similar to those reported for extinct cetaceans and mosasaurs, which were interpreted as traces of aggressive encounters. Nevertheless, Temnodontosaurus differs from these other marine amniotes in the absence of pathologies in the vertebral column, consistent with the pattern previously documented in ichthyosaurs. We did not detect any instances of avascular necrosis in Temnodontosaurus from southern Germany, which may reflect a shallow diving life style. This study is intended to provide baseline data for the various types of observed pathologies in large ichthyosaurs occupying the ‘apex predator’ niche, and potentially clarifies aspects of species-specific behavior relative to other ichthyosaurs and marine amniotes.

Mary Anning, Alfred Nicholson Leeds and Steve Etches. Comparing the three most important UK ‘amateur’ fossil collectors and their collections

Mary Anning, Alfred Nicholson Leeds and Steve Etches form part of a long line of individuals who furnished a substantial addition to our understanding of marine and terrestrial ecosystems through collecting significant numbers of superb fossils. For all three collectors, fossils became a factor that dominated their lives, and their fossil collecting led to the discovery of numerous taxa new to science. Extensive collecting was made possible by the fortunate circumstances of living ‘in the right place at the right time’, close to fine-grained UK Jurassic deposits (Lagerstätten) with well-preserved large Jurassic marine reptiles. All three were highly-motivated and developed a considerable skill sets for discovering, collecting, preparing, conserving and displaying fossils. They developed personal and professional interactions with family and friends, and university and museum professionals, although their collecting resulted in variable recognition of their work. Each collector can be considered a complex mix of amateur and professional: Mary Anning, a professional fossil collector and amateur palaeontologist; Alfred Leeds transitioned from amateur to professional fossil collector, but remained an amateur palaeontologist; and Steve Etches has remained an amateur fossil collector and palaeontologist. However, all three exhibited an entirely professional outlook to collecting, and should be considered professionals of the highest degree. The impact of Mary Anning, Alfred Nicholson Leeds and Steve Etches has been critical for the development of Palaeontology as a science, and without whom palaeontology, with all its associated benefits to a wide scientific and non-scientific audience, would not be as rich as we currently know it.

Ecomorphological diversifications of Mesozoic marine reptiles: the roles of ecological opportunity and extinction

AbstractMesozoic marine ecosystems were dominated by several clades of reptiles, including sauropterygians, ichthyosaurs, crocodylomorphs, turtles, and mosasaurs, that repeatedly invaded ocean ecosystems. Previous research has shown that marine reptiles achieved great taxonomic diversity in the Middle Triassic, as they broadly diversified into many feeding modes in the aftermath of the Permo-Triassic mass extinction, but it is not known whether this initial phase of evolution was exceptional in the context of the entire Mesozoic. Here, we use a broad array of disparity, morphospace, and comparative phylogenetic analyses to test this. Metrics of ecomorphology, including functional disparity in the jaws and dentition and skull-size diversity, show that the Middle to early Late Triassic represented a time of pronounced phenotypic diversification in marine reptile evolution. Following the Late Triassic extinctions, diversity recovered, but disparity did not, and it took over 100 Myr for comparable variation to recover in the Campanian and Maastrichtian. Jurassic marine reptiles generally failed to radiate into vacated functional roles. The signatures of adaptive radiation are not seen in all marine reptile groups. Clades that diversified during the Triassic biotic recovery, the sauropterygians and ichthyosauromorphs, do show early diversifications, early high disparity, and early burst, while less support for these models is found in thalattosuchian crocodylomorphs and mosasaurs. Overall, the Triassic represented a special interval in marine reptile evolution, as a number of groups radiated into new adaptive zones.

New data on the palaeobiogeography of Early Jurassic marine reptiles: the Toarcian ichthyosaur fauna of the Vocontian Basin (SE France)

New data on the palaeobiogeography of Early Jurassic marine reptiles: the Toarcian ichthyosaur fauna of the Vocontian Basin (SE France)

Short Note: Second Jurassic marine reptile from the Antarctic Peninsula

Except for the rich record from the Neuquen Basin (e.g. Gasparini & Fernández 2006), Jurassic southern Gondwanan marine reptiles are relatively rare. A tooth discovered in the Bean Peaks, Ellsworth Land, Antarctic Peninsula (Fig. 1) represents the southernmost, and only the second record of Jurassic marine reptiles from the Antarctic Peninsula. Comprising a single, incomplete tooth, the specimen is unable to be assigned to a species, but the paucity of Gondwanan Jurassic marine reptile material means this find adds significant palaeobiogeographical information.

THE ALFRED LEEDS FOSSIL VERTEBRATE COLLECTION OF THE NATIONAL MUSEUM OF IRELAND—NATURAL HISTORY

Alfred nicholson Leeds (1847–1917) is famous among vertebrate palaeontologists for amassing an invaluable collection of fossil vertebrates from the Middle Jurassic aged ‘Oxford Clay’ deposits of the Peterborough district in the UK, throughout the late nineteenth and early twentieth centuries. Part of his collection was acquired by the national Museum of Ireland— natural History in november 1893 but has not previously been described. This fossil material includes a suite of Jurassic marine reptiles: crocodiles, plesiosaurs and ichthyosaurs. There are no examples, however, of the giant fish Leedsichthys; the remains of which are commonly found among the fauna of the Oxford Clay Formation. Despite representing only a very small fraction of the total Leeds Collection, the specimens in Ireland are significant historically, and have scientific value in their own right. For the first time, in this paper, a historical review of the Dublin Leeds Collection is presented, the fossil specimens described and a long-lost piece of important documentation is presented.

FIRST RECORD OF METRIORHYNCHUS (REPTILIA: CROCODYLIFORMES) IN THE BATHONIAN (MIDDLE JURASSIC) OF THE EASTERN PACIFIC

Jurassic marine reptiles are best known from the study of European Jurassic collections. The record of these reptiles encompasses most of the period, but that of Aalenian–Bathonian rocks is quite incomplete (Andrews, 1913; Brown, 1981; Buffetaut, 1982; Godefroit, 1994; Bardet, 1995; O'Keefe, 2001; McGowan and Motani, 2003). South American marine reptiles of the early Middle Jurassic are especially significant because they contribute to fill this gap of taxonomic and paleogeographic information (Fernandez, 1994, 1999, 2003; Spalletti et al., 1994; Gasparini, 1997; Gasparini et al., 2000). The largest amount and diversity of Jurassic marine reptiles of the Southern Hemisphere was found in northwestern Patagonia, in the Neuquen Basin (Yrigoyen, 1991; Fig. 1). These reptiles dominate in Tithonian rocks cropping out at numerous sites of the basin (Gasparini and Fernandez, 1996; Spalletti et al., 1999). On the contrary, Middle Jurassic marine reptiles are restricted to Chacaico Sur area, southeast of the Neuquen Province (Fig. 1). There, until present, ichthyosaurs, plesiosaurs, and a crocodile vertebra were found in the upper part of Los Molles Formation, Cuyo Group (Lower Bajocian), and pliosaurs and plesiosauroids were found in the lower part of Lajas Formation, Lower Callovian (Gasparini and Spalletti, 1993; Fernandez, 1994, 1999; Spalletti et al., 1994; Gasparini, 1997). Figure 1 —The Neuquen Basin in west-central Argentina, showing the location of Chacay Melehue section. The crocodile remains proceed from Los Molles Formation. Base map from Digregorio et al. (1984) Recently, during field work performed by the biostratigraphy students of the Geological Sciences Department (University of Buenos Aires) in the area of Chacay Melehue, Neuquen Province (Fig. 1), two of the authors (MC and DL) took part in the finding and extraction of the skull and postcranium …

Jurassic marine reptiles of the Neuquén Basin: records, faunas and their palaeobiogeographic significance

Abstract The largest diversity of Jurassic marine reptiles from Gondwana has been recorded in the Neuquén Basin. Although the Early Jurassic records are limited, the records from the Middle Jurassic, especially the early Bajocian plesiosaurs and ichthyosaurs, are unique in the world. The highest abundance and taxonomic diversity is recorded from the Late Jurassic (Tithonian). Pleurodiran (Notoemys) and cryptodiran turtles (Neusticemys), ichthyosaurs (Ophthalmosaurus, Caypullisaurus), pliosaurs (Pliosaurus, Liopleurodon) and crocodilians (Geosaurus, Metriorhynchus, Dakosaurus) are members of this rich marine herpetofauna. Except for Notoemys, the other reptiles are pelagic. Their habits and large size (Caypullisaurus, Liopleurodon, Dakosaurus) suggest that they entered the sheltered Neuquén Basin occasionally, possibly for reproduction in protected areas. The model of a protected basin, open to the Pacific Ocean through gaps in an emergent by island-arc complex, fits well with the ecological requirements inferred for most of the pelagic reptiles. The Caribbean Corridor may also have played a significant role as a seaway at least during the Middle Jurassic and probably before. New findings in Tithonian and Berriasian sediments of the Neuquén Basin suggest that there was no massive extinction among the marine herpetofauna at the Jurassic-Cretaceous boundary.

Thomas Hawkins, Lord Cole, William Sollas and all: casts of Lower Jurassic marine reptiles in the Geological Museum, Trinity College, Dublin, Ireland

A number of casts of complete or portions of plesiosaurs from the Lower Jurassic of England are stored or displayed in the Geological Museum of Trinity College, Dublin. The historical significance of these has only relatively recently been realised. They include specimens from the collections of Thomas Hawkins, William Willoughby Cole the Earl of Enniskillen, and the Bristol City Museum. They came into the possession of Trinity College, Dublin either by donation from the Geological Society of Dublin in 1848 or from William Johnston Sollas in the late 1800s. These casts include the holotype of Thalassiodracon hawkinsi (Owen, 1838); a �sternum� and �scapula� illustrated by Thomas Hawkins and now referable to Eurycleidus arcuatus (Owen, 1840); a complete skeleton of Plesiosaurus macrocephalus Owen, 1838; the right and left side of a skull of Eurypterygius communis(Conybeare, 1822) the original of which was at the Birmingham Philosophical Institution; the skull and the right front flipper of Rhomaleosaurus megacephalus(Stutchbury, 1846); and a badly damaged cast of Attenborosaurus conybeari (Sollas, 1881). The latter two examples are important because the originals once in Bristol were destroyed in 1940 during the Second World War.

First occurrence of a gigantic pliosaurid plesiosaur in the late Jurassic (Kimmeridgian) of Mexico

Abstract Reinvestigation of a partial vertebral column from the Kimmeridgian La Caja Formation of Mexico, housed in the University of Linares (Mexico), and previously attributed to a dinosaur, proves to be from a very large pliosaurid plesiosaur. This specimen represents the first plesiosaur described from the Jurassic of Mexico. Its length has been estimated at 15 metres and, as a juvenile, is considered to be one of the largest Jurassic marine reptiles. The remains of this animal are here described. The morphology of the vertebral column is not diagnostic beyond family level. Large pliosaur vertebrae of a similar size are known from the Upper Jurassic of Europe, and are often referred to the genera Liopleurodon or Simolestes but these identifications are based only upon the size of the centra and have no taxonomic justification. A portion of rostrum with teeth was discovered together with the vertebral column but is unfortunately now lost. The Mexican pliosaur fills geographical and chronological gaps between western Tethys and South American pliosaurs, and is an additional support to the hypothesis of a Hispanic corridor linking at least temporarily the NW European marine province with the western South American marine (Pacific) realm during the late Jurassic.

A Catalogue of the Type, Figured and Cited Fossils in the Nottingham Natural History Museum, Wollaton Hall, Nottingham, U.K.

Nottingham Corporation's first museum was established in 1867 at Exchange Buildings, Nottingham. The geology collections were transferred to the Nottingham University College Natural Sciences Museum, which opened in 1881, and placed under the care of the Professor of Natural History. Since 1926 the geology collections have been located at Wollaton Hall. Type, figured and cited specimens in the Nottingham Natural History Museum, Wollaton Hall, are listed. Strengths lie in Nottinghamshire and Derbyshire Pleistocene mammals. Lower Jurassic marine reptiles, Triassic footprints and Coal Measures plants and Wenlock Limestone invertebrates from the Dudley area, West Midlands.

The plesiosaur's birthplace: the Bristol Institution and its contribution to vertebrate palaeontology

The Bristol Institution for the Advancement of Science, Literature and the Arts opened in 1823. The science expounded at the Institution was an anti-Lamarckian ideology based on Paleyan natural theology and the Aristotelean Great Chain of Being. Pioneering work on Jurassic marine reptiles by W. D. Conybeare and H. T. De la Beche in 1821-1824 used material from its collection, and it was at the Institution that Conybeare first publicly announced the discovery of the first complete plesiosaur. In the early 1830s, Henry Riley and the second curator Samuel Stutchbury first described Permo-Triassic reptiles including Thecodonlosaurus. Riley was one of the earliest exponents of Geoffroyan comparative anatomy in Britain. The Institution declined under financial pressures, eventually to be taken over by Bristol City Council in 1894. Its main contribution to science was its collection of fossil and Recent vertebrates. Louis Agassiz drew upon its fossil fishes for Poissons fossiles, and Richard Owen used the reptiles for his British Association Report of 1841-1843. Much of the collection was destroyed in 1940 but much also remains.

The plesiosaur's birthplace: the Bristol Institution and its contribution to vertebrate palaeontology

Abstract The Bristol Institution for the Advancement of Science, Literature and the Arts opened in 1823. The science expounded at the Institution was an anti-Lamarckian ideology based on Paleyan natural theology and the Aristotelean Great Chain of Being. Pioneering work on Jurassic marine reptiles by W. D. Conybeare and H. T. De la Beche in 1821-1824 used material from its collection, and it was at the Institution that Conybeare first publicly announced the discovery of the first complete plesiosaur. In the early 1830s, Henry Riley and the second curator Samuel Stutchbury first described Permo-Triassic reptiles including Thecodonlosaurus . Riley was one of the earliest exponents of Geoffroyan comparative anatomy in Britain. The Institution declined under financial pressures, eventually to be taken over by Bristol City Council in 1894. Its main contribution to science was its collection of fossil and Recent vertebrates. Louis Agassiz drew upon its fossil fishes for Poissons fossiles , and Richard Owen used the reptiles for his British Association Report of 1841-1843. Much of the collection was destroyed in 1940 but much also remains.